Related Clues:

• ___-Columbian
• Keep out
• Start to mature
• Ante-
• Prior to
• Blackball
• See 6-Across
• Historic beginning
• ___-1900 (old)
• Prefix with nuptial
• Prefix with Columbian
• See 39-Across
• Start with school
• Season opener?
• Axle, e.g.